Basically, when a programmer interested in Rockbox is thinking "I'd like to help out, but I can't think of anything to do" we point them at the Feature Request and Bug trackers.
If you post here, it will only get seen by forum members. The absolute VAST majority of them are users, who will do little more than say "Yeah, that's a really good idea, but I lack the skill to work on it" so the best hope of having anything happening is to register and put it in the proper place. It's far from guaranteed, but it does help a little.